Neural correlates of auditory function and training in older adults

描述（由申请人提供）：许多老年人在背景噪音中难以感知语言。为什么这种情况只发生在一些老年人身上，而不是所有的老年人身上，这个问题目前还没有答案。我们的长期目标是了解老年人在噪音中语音感知的生物学基础，并利用这些知识通过训练来提高感知能力。越来越多的证据表明，听觉感觉系统（包括耳蜗力学和脑干）是动态的，可以通过短期（训练）和终身（语言和音乐）经验来塑造。正常的语言交流依赖于神经系统对声音的准确转录，尤其是在嘈杂的环境中。在老龄化人口中，这种转录过程的失败代表着巨大的社会和经济成本，大量资源被投入到可能不起作用的治疗中。在诊断和治疗方案的评价中很少有客观的评价。此外，越来越多的证据表明，听觉外围区是由高级中枢通过传出系统调节的，以帮助在背景噪音中倾听。这种贡献仍有待于在人类物种中进行任何细节的表征和/或量化。因此，我们的目标是确定老年人在噪音中语音的脑干转录，这种转录与耳蜗力学测量的关系，以及转录随训练的可塑性。我们的中心假设是转录准确性和耳蜗力学的破坏是听力噪音障碍的因素，这种破坏可以通过干预来补救。这项工作的结果将揭示老年人在噪音中语音感知的感觉机制，并确定短期训练产生的基本感觉回路的可塑性。这一结果将对我们对老年人感觉功能的认识和客观评价产生积极的影响。

DESCRIPTION (provided by applicant): Many older adults experience excessive difficulty perceiving speech in background noise. Why this occurs for some, but not all older individuals is a question that currently has no answer. Our long-term goal is to understand the biological bases of speech-in-noise perception in older adults and to use that knowledge to improve perception through training. Converging evidence indicates that the auditory sensory system (including cochlear mechanics and brainstem) is dynamic and can be shaped by short-term (training) and lifelong (language and music) experience. Normal verbal communication depends on the accurate transcription of sound by the nervous system, especially in noisy backgrounds. Failure of this transcription process in the aging population represents a huge social and financial cost, and considerable resources are invested in treatments that may not work. Little objective assessment exists in diagnosis and evaluation of treatment options. Further, there is emerging evidence that the auditory periphery is modulated by higher centers via the efferent system to aid listening in background noise. This contribution remains to be characterized and/or quantified in any detail in the human species. Accordingly, our objectives are to determine brainstem transcription of speech sounds in noise in older adults, how this transcription relates to measures of cochlear mechanics, and the plasticity of transcription with training. Our central hypothesis is that disruption of transcription accuracy and cochlear mechanics are factors in listening-in-noise impairments, and that disruption can be remedied by intervention. The outcome of the proposed work will reveal sensory mechanisms linked to speech perception in noise in older adults and determine plasticity of basic sensory circuitry arising from short-term training. This outcome will have a positive impact on our understanding and objective assessment of sensory function in aging adults.